diff --git a/source/ch7_recursion.ptx b/source/ch7_recursion.ptx
index 5f1da65..f04f71c 100644
--- a/source/ch7_recursion.ptx
+++ b/source/ch7_recursion.ptx
@@ -238,6 +238,7 @@ def main():
 main()
         </code>
     </program>
+    </listing>
     
     <p><idx>separation of concerns</idx>
         The key insight here is called the <term>separation of concerns</term>. The public <c>sum_array</c> method provides a user-friendly interface—callers just pass an array and get the sum. Users don't need to know about indexes or how the recursion works internally. The private <c>_sum_helper</c> method handles the recursive logic with the extra parameter needed to track progress through the array.
diff --git a/source/ch8_filehandling.ptx b/source/ch8_filehandling.ptx
index ba5d0cf..542ebfb 100644
--- a/source/ch8_filehandling.ptx
+++ b/source/ch8_filehandling.ptx
@@ -73,10 +73,10 @@
 
 
         <p>
-            We will now create a <c>File</c> object. It is important to create a meaningful name for the <c>File</c> object. We will call ours <c>myFile</c>, and we will call our class <c>CreateFileObject</c>.
+            We will now create a <c>File</c> object. It is important to create a meaningful name for the <c>File</c> object. We will call ours <c>myFile</c>, and we will call our class <c>CreateFileObject</c>. <xref ref="create-file-object-java" text="type-global"/> shows the code to create a <c>File</c> object in Java. 
         </p>
-        
-        <program xml:id="create-file-object-java" interactive="activecode" language="java" add-files="myfile-created">
+        <listing xml:id="create-file-object-java">
+        <program interactive="activecode" language="java" add-files="myfile-created">
             <code>
 import java.io.File;
 
@@ -90,6 +90,7 @@ public class CreateFile {
 }
             </code> 
         </program>
+        </listing>
 
         <note>
             <p>
@@ -103,10 +104,10 @@ public class CreateFile {
         </p>
 
         <p>
-            First, lets look at the equivalent Python code:
+            <xref ref="create-file-python" text="type-global"/> shows the equivalent code to create a file in Python.
         </p>
-        
-        <program xml:id="create-file-python" interactive="activecode" language="python">
+        <listing xml:id="create-file-python">
+        <program interactive="activecode" language="python">
             <code>
             filename = "newfile.txt"
             print("Attempting to write to '" + filename + "' using 'w' mode...")
@@ -120,12 +121,13 @@ public class CreateFile {
 
             </code> 
         </program>
+        </listing>
 
         <p>
-            Now, let's look at Java code that accomplishes the same task:
+            <xref ref="create-file-java" text="type-global"/> shows the equivalent code to create a file in Java.
         </p>
-        
-        <program xml:id="create-file-java" interactive="activecode" language="java">
+        <listing xml:id="create-file-java">
+        <program interactive="activecode" language="java">
             <code>
             import java.io.File;
             import java.io.IOException;
@@ -148,6 +150,7 @@ public class CreateFile {
             }
             </code> 
         </program>
+        </listing>
 
         <note>
             <p>